The Pediatric General Clinical Research Center at the University of Colorado School of Medicine is a non-categorical center that provides support for a wide range of research protocols designed, directly or indirectly, to improve health care for infants and children. This renewal proposal includes 87 new or extensively revised individual clinical research protocols that have been submitted by both senior and junior investigators with their own grant support and have been approved by the Center Advisory Committee. Major research topics include normal and abnormal growth and development, extremely low birth weight infants, micronutrients, substrate and energy metabolism, obesity, diabetes prevention, tissue transplants, immunology, cystic fibrosis and other pulmonary diseases, fragile X syndrome, polycystic kidney disease, chronic hepatic and gastrointestinal disease, blood coagulation defects, adolescent pregnancy and HIV infection. The Pediatric GCRC facilities for which support is requested include a 7-bed pediatric inpatient unit. New features and activities proposed for this unit are a nutrition laboratory; and research nursing support and space for long-stay ambulatory research. The nursing staff of this unit will also support pediatric, scatterbed research. Other facilities are: a neonatal scatterbed unit (2 beds); a short-term ambulatory unit; a core laboratory, and an administrative unit. Key personnel include research nursing staff, a research dietitian and diet technician, biostatistician, medical technologists.